Tank cleaning machine

ABSTRACT

Hydraulic tank-cleaning apparatus having a stationary housing, a second rotatable housing for rotation about the stationary housing axis and a third rotatable nozzle housing for rotation about an axis normal to the stationary housing axis. Apparatus is driven by means of an impeller and a compact reduction gear train comprising a first and second set of spur and pinion gear assemblies coaxially arranged along a first and second shaft respectively for driving both housings at a speed substantially reduced from that of the impeller.

United States Patent Rocker Jan. 25, 1972 [54] TANK CLEANING MACHINE 3,275,241 9/1966 Saad ..239/227 [72] Inventor: James H. Rucker, San Ramon, Calif. Primary Examiner uoyd L g [731 Assignees: Sybron Corporation, Rochester, N.Y.; Attarney-Theodore B. Roessel Cloud Company, Alameda, Calif. [22] Filed: May 18, 1970 [57} ABSTRACT Hydraulic tank-cleaning apparatus having a stationary hous- [21] Appl. No.. 38,256 ing, a second rotatable housing for rotation about the stationary housing axis and a third rotatable nozzle housing for rota- 52 us. ca ..239/227 tion about an axis normal to the Stationary housina flxis- P- 5 1 Cl os 3 00 paratus is driven by means of an impeller and a compact [58] Field of Search ..239/227 reduction g train compl'ising a first and Second Set of P and pinion gear assemblies coaxially arranged along a first and 5 References Cited second shaft respectively for driving Iboth housings at a speed substantially reduced from that of the impeller. UNITED STATES PATENTS 6 Claims, 4 Drawing Figures 3,326,468 6/1967 Bristow et al ..239/227 PATEMED JANB IQ Z 3,637,138

mm 12w 2 INVENTOR. JAMES H. RUCKER ATTORNEY PATENTED JANZSLQTZ FIG. 2

INVENTOR.

JAMES H, RUCKER ATTORNEY TANK CLEANING MACHINE FIELD OF INVENTION This invention relates to tank-cleaning machines and more particularly to tank-cleaning machines adapted to be suspended on a supply hose in cargo tanks of railway cars and marine tankers, storage tanks, reactors, and the like.

BACKGROUND OF THE INVENTION Tank-cleaning machines of the general type described herein are shown in the following: Butterworth U.S. Pat. No. 1,806,740; Veneziano U.S. Pat. No. 2,661,241; Pedrick U.S. Pat. No. 2,916,268; Lione U.S. Pat. No. 2,917,243; and Kennedy U.S. Pat. No. 3,052,574.

Tank-cleaning machines of the type disclosed in the aforementioned patents have heretofore utilized a source of liquid for operating the machine. Conventionally this source of liquid drives a propeller mounted on a propeller shaft which passes through a gearbox. Tank-cleaning machines of this type are subjected to very severe operation conditions while at the same time the user requires substantially maintenance free operation. For instance, tank-cleaning machines, when used on a marine tanker, are often exposed to concentrated caustic cleaning solutions at elevated temperatures and the machine used continuously for long periods of time where for instance the cargo tanks of a tanker are cleaned at sea during the tankers empty trip to a port where it loads cargo. During a single trip of this type, a tank-cleaning machine is subjected to extremely corrosive conditions and the user of the machine cannot tolerate machine failures at sea. Bristow et al., in U.S. Pat. No. 3,326,468 discloses a tank-cleaning machine involving the use of spur gears instead of commonly used worm gears in the drive train which eliminates many problems connected with prior art tank-cleaning machines and which has proved highly successful for its purpose.

Prior art tank-cleaning machines of the type disclosed by Bristow et al., although highly reliable and useful for marine purposes, have found only limited application in industrial and allied areas i.e., the cleaning of tank cars and trucks, due primarily to the size of the unit as presently available. Thus, while in the marine area the hatches providing access to the interior of the tanks to be cleaned have been designed for the use of tank-cleaning devices and are, therefore, of sufficient size to handle the available tank-cleaning equipment, tanks, reactors, and the like used in the nonmarine areas have not been so designed and, therefore, reliable tank-cleaning equipment has not been generally available for the cleaning of tanks in the nonmarine field.

In adapting tank-cleaning apparatus for utilization in a nonmarine field, mere reduction of size of components is by itself not responsive to the problem since the machine must maintain its reliability, its ability to operate under severe operating conditions, and must be able to deliver substantially the same quantities of cleaning fluid at substantially the same pressure as the marine unit. Bristow, in U.S. Pat. No. 3,464,632 represents one attempt to reduce the size of tank-cleaning apparatus by the utilization of planetary gears in the drive mechanism. It has been found, however, that such apparatus lacks the required reliability and ability to operate under severe operating conditions.

OBJECTS OF THE INVENTION Accordingly, it is an object of this invention to provide tankcleaning apparatus having a reduced overall outside diameter without sacrificing reliability, durability, efficiency and output.

Another object of this invention is to provide a tank-cleaning apparatus in which the driving mechanism retains the durability and reliability of a spur gear train while at the same time is substantially compact.

Another object of this invention is to utilize a driving mechanism which is readily accessible and easily maintained while at the same time is substantially sealed and separated from the stream of cleaning fluid.

SUMMARY OF THE INVENTION These and other objects of the invention are accomplished with the machine structure illustrated in the attached drawing and described below wherein there is provided a stationary housing having a first interior passageway designed to communicate with a source of cleaning fluid and an enclosed fluidtight gearbox, a second housing rotatably mounted on the stationary housing for rotation about the axis of the first housing and having a second interior passageway communicating with the first interior passageway of the stationary housing. A third housing is rotatably mounted on the second housing for rotation about an axis substantially normal to the axis of the stationary housing and having nozzles communicating with the second interior passage of the second housing. Impeller means are positioned in the first interior passageway of the stationary housing and the impeller shaft extends into the gearbox. A compact reduction gear train is provided in the gearbox for driving the second and third rotatable housing in response to rotation of the impeller and at a'speed substantially slower than the speed of rotation of the impeller. By virtue of the arrangement of the reduction gear drive of the apparatus of this invention, the gearbox is substantially reduced in size thereby substantially reducing the outside diameter of the tank'cleam ing apparatus while at the same time performance of the machine is not diminished.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of the tank-cleaning machine of this invention.

FIG. 2 is a vertical sectional view of the machine of this invention.

FIG. 3 is a schematic view of the train of driving gears of the tank-cleaning machine of FIG. 2.

FIG. 4 is a horizontal section through line 4-4 of a portion of the tank-cleaning machine of FIG. 2.

DESCRIPTION OF THE INVENTION Referring now in detail to the drawings, and particularly to FIG. 1, the tank-cleaning machine illustrated therein includes a stationary housing 11 having a fluid inlet 12 which is adapted for connection to a hose pipe by means of threaded adapter 121 which the tank-cleaning machine may be suspended in a tank to be cleaned. The lower portion of the stationary housing 11 defines gearbox I3 and a second rotary housing 1 4 is mounted on stationary housing 11 for rotation about the axis of stationary housing 11. Gearbox 13 is of substantially the same or smaller diameter as second housing 14 which allows for the use of the machine of this invention for the cleaning of tanks where the access ports thereof are too small for the use of prior art tank-cleaning machines which have gear trains requiring gear boxes of substantially larger diameter. A third rotary housing 16 is mounted on second housing 14 for rotation about an axis normal to the axis of stationary housing 11 and carrying a pair of eccentrically directed nozzles 17.

Referring now to FIG. 2, stationary housing 11 is provided with upper cylindrical portion 217 which defines interior passageway 18 terminating in a constricted portion 19, which in combination with bearing and seal means described in more detail hereinafter, serves to separate passageway 18 from the interior of gearbox 13. In the preferred embodiment of this invention, stationary housing 11 incorporates gearbox 13, constricted portion 19 and cylindrical portion 17 as an integral unit. Constricted portion 19 also defines shaft passage 21. Lip 22 is provided at the bottom of upper cylindrical portion 17 for mounting annular bevel gear 23. Elevel gear 23 is recessed on its upper surface for receiving collar 124 of bushing 24 and on its inner surface for mounting on lip 22. Bevel gear 23 is affixed at housing 11 by conventional means, preferably by providing a key on lip 22 and a corresponding recess in bevel gear 23 for receiving the key. O-ring 26 provides a fluidtight seal and wear cup27 is positioned about bushing 24 in the manner shown. Hose adapter 121 is threadably mounted on the upper end of cylindrical portion 217 and is provided with depending skirt portion 122. Lock bolt 123 prevents rotation of adapter 121 during operation.

Second housing 14 is mounted for rotation about the axis of stationary housing 11 by means of lower ring member 28 carried by second housing 14 which is adapted to be received by the outer surface of wear cup 27. Second bushing 29 and wear cup 31 are positioned on upper ring member 32 of housing 14 and cylindrical portion 217 for rotation of housing 14 with respect to stationary housing 11. O-ring 33 provides a fluidtight seal.

Second housing 14 is provided with cylindrical extension 34 on which third rotary housing 16 is rotatably carried by means of a pair of bushings 36, wear cups 37 and cover plate 39 which is held in place by a plurality of bolts 41. Orings 38 provide fluidtight seals. The outer edge of cover plate 39 is turned in for defining a seat for collar 136 one of said bushings 36 and ring 35 is provided on cylindrical portion 34 of housing 14 to define a seat for collar 136 of said other bushing 36.

The interior of second rotary housing 14 defines a second interior passageway 42 which communicates with first interior passageway 18 through apertures 43 in upper cylindrical portion 217. Apertures 44 of cylindrical extension 34 provide communication from second passageway 42 to nozzles 17. Each of nozzles 117 is provided with a set of flow straightener vanes 46.

Bevel gear 47 is held in position on the inner end of third rotary housing 16 by means of snap ring 48 positioned in an annular groove 49 provided at the inner end of third housing 16. Bevel gear 47 is in meshed relationship with bevel gear 23 on stationary housing 11 so that as second housing 14 is rotated about stationary housing 11, third housing 16 is driven about an axis substantially normal to the axis of stationary housing 11. Bevel gears 23 and 47 have a large number of teeth, but the numbers of teeth on the two gears differ by one so that the spread pattern delivered by the nozzles 117 is nonrepetitive for any extremely large number of revolutions of the third housing 16.

In order to allow for the manual rotation of nozzles 117 during periods of nonoperation and to prevent damage to the drive train in the event the nozzles are obstructed during operation of the tank-cleaning machine, friction clutch means, shown generally at 51, is provided and comprises clutch ring 52 seated in annular channel 53. Annular channel 53 communicates between the second interior passageway 42 and bevel gear 47. Prior to the application of hydraulic pressure, third housing 16 is free to rotate with respect to gear 47. During operation fluid pressure urges clutch ring 52 against a surface of gear 47 and against the sides of annular channel 53 thereby connecting housing 16 to gear 47. In the event nozzles 17 are obstructed by a force. greater than the driving force, the coefficient of friction of clutch ring 52 is overcome allowing gear 47 to rotate independently of housing 16. Clutch ring 52 is formed of resilient, wear resistant material, preferably a synthetic rubber material such as for example Buna-n or a fluoroelastomer.

Referring to FIGS. 2 and 3, stater 54 is mounted in fluid inlet 12 by means of snap ring 56 and turbine 57 is positioned immediately below stater 54 and mounted on turbine drive shaft 58. Turbine drive shaft 58 extends into gearbox 13 and is journaled by suitable bearing means 59 carried by bottom plate 61. Bottom plate 61 is attached to gearbox 13 by conventional means, such as for example, a plurality of bolts 62 and is sealed by O-ring 63 to prevent entrance of fluid into gearbox 13.

The entrance of shaft 58 into gearbox 13 is preferably sealed in the following manner. Bearing and seal cartridge, shown generally as 64 is coaxially positioned in shaft passage 21. Cartridge 64 is provided with a sleeve portion 65 and a collar 66 having a diameter larger than shaft passage 21 to prevent fluid pressure from forcing cartridge 64 to move axi- .ally downwardly along shaft 58 during operation. The outside diameter of sleeve portion 65 of cartridge 64 is such as to allow a snug fit of cartridge 64 in shaft passage. The length of sleeve portion 65 is selected to allow extension of cartridge 64 through the entire length of shaft passage 21. Sleeve portion 65 is provided with passages 67 which, when cartridge 64 is positioned in shaft passage 21, communicate between fluid discharge ports 71 provided in the wall of shaft passage 21 and shaft 58. Sealing between the outer surface of sleeve portion 65 and the surface of shaft passage 21 is provided by upper and lower O-rings situated in upper and lower grooves, 73 and 74 respectively, provided on the outer surface of sleeve portion 65. Extending upwardly from and carried by collar 66 are posts 76 which carry ring 77. Ring 77 is used for gripping and handling cartridge 64 for insertion and removal from shaft passage 21.

Shaft bearing 78 is pressed into the lower end of sleeve portion 65 of cartridge 64. Removable sleeve 81 is provided at the upper end of sleeve portion 65 of cartridge 64 for retaining upper shaft seal 79 and lower shaft seal 82. In addition, removable sleeve 81 carries seal 83 which provides a seal between removable sleeve 81 and cartridge 64. Removable sleeve is provided with passages 84 for providing communication between fluid discharge ports 71, passages 67 in sleeve 65 and shaft 58 whereby fluid leaking along shaft 58 is forced out through the aforementioned passages by rotation of shaft 58 and to the outside through opening 72 formed between stationary housing 1 1 and secondary rotary housing 14.

If desired, spacers (not shown) may be interposed between the undersurface of collar 66 of cartridge 64 and the shoulder formed at the intersection of constricted portion 19 of stationary housing 11 and shaft passage 21. During operation, rotation of shaft 58 will cause wear at the upper and lower shaft seals, 78 and 82. By removing one or more of such spacers cartridge 64 and its accompanying bearing and seals are repositioned along shaft 58 thereby to provide new sealing areas between upper and lower shaft seals 78 and 82 and shaft 58.

Referring to FIGS. 2 and 3 shaft pinion 91 is affixed to drive shaft 58 immediately above bearing 59 in meshed relationship with gear reduction train designated generally as 92.

Idler shaft 93 and final drive shaft 94 are journaled at their lower ends in bosses 95 and 96 provided in bottom plate 61, with the final drive shaft boss 96 being more raised than idler shaft boss 95. Bearing means 97 are provided for rotation of each shaft in its respective journal. Each shaft is provided with a plurality of spur and pinion gear assemblies coaxially arranged along the shaft. In the embodiment shown in FIG. 3, idler shaft 93 is provided with three spur and pinion gear assemblies 101, 103 and 105. Final drive shaft 94 is likewise provided with two spur and pinion gear assemblies 102 and 104. Each assembly is free to rotate on its respective shaft independently of the other assemblies on the same shaft and independently of the rotation of the shaft. Spur gear 106 is fixed to the final drive shaft 94. Bushing means 107 made of suitable low friction material such as for example oil impregnated bronze are provided between the assemblies and each shaft for independent rotation of the assemblies with respect to the shaft rotation. The bushing means 107 are provided with collars 108 to provide bearing surfaces between the individual assemblies. It is preferred that each spur and pinion gear assembly be an integral body for strength and ease of assembly and maintenance. However, if desired, the spur gear and pinion gear of each assembly may be separately formed and joined together by means of pins or the like.

Idler shaft 93 and final drive shaft 94 are located with respect to turbine drive shaft 58 so that pinion 91 meshes with the spur gear of assembly 101 and the pinion of assembly 101 meshes with the spur gear of assembly 102 and so forth as illustrated. Final drive gear shaft extends through the top of gearbox 13 and O-ring and bushing retainer 111, O-ring 112 and bushing 113 are provided as an upper journal for final drive shaft 54 and fluid seal for gearbox 13. Final drive pinion 109 is affixed at the upper end of final drive shaft 94 and meshes with ring gear 114 which is carried by snap ring 116 positioned in the annular groove 117 in the lower interior wall of second rotary housing 14. Ring gear 114 is provided with a plurality of outwardly extending lugs 1113, any one of which contact stop 119 provided on the lower interior wall of second rotary housing 14. In this manner, assembly of ring gear 114 in housing 14 is expedited and rotation of ring gear 114 is transmitted to housing 14 during operation.

In operation, cleaning fluid is led into the tank cleaning machine of this invention through fluid inlet 12 by means of hose or pipe suitably connected at the upper end of the machine. The fluid passes stater 54 and is impelled against the blades of turbine 57 causing it to rotate with its shaft 58. The fluid then passes into first interior passageway 18, through apertures 43 and into second passageway 42 of second rotary housing 14. Fluid then passes through apertures 44 and out through nozzles 17 in a concentrated stream. As previously described, fluid pressure through channel 53 urges clutch ring 52 against the channel sides and against a surface of gear 47 thereby connecting housing 16 and gear 47.

The rotation of shaft 58 as previously described, causes pinion 91 to rotate which in turn drives the spur gear of as sembly 101 of intermediate drive shaft 93 which in turn through the pinion of assembly 101 drives the spur gear of assembly 102 of the final drive shaft 94. The pinion gear of assembly 102 drives the spur gear of assembly 103 and so forth with each translation between intermediate drive shaft 93 and final drive shaft 94 resulting in a reduction in rotational speed. Final drive speed is achieved between the pinion of assembly 105 and spur gear 106 which drives final drive shaft 54. Final drive pinion 109, driven by shaft 54, drives ring gear 114 causing second rotary housing 14 to rotate about the axis of stationary housing 11. As stationary housing 11 rotates, bevel gear 47, which as previously described is meshed with bevel gear 23 of stationary housing, drives third rotary housing 16 about an axis substantially normal to the axis of stationary housing 11.

Wear cups 31 and 37 are designed to be expendable and are preferably constructed of noncorrosive metal such as stainless steel or bronze. Bushings 24, 29, and 36 are preferably constructed of a wear resistant low coefficient of friction material such as for example, nylon or teflon. It has been observed that unless some means are provided for locking bushings 24, 29 and 36, these bushings will rotate during operation of the machine causing an erosion of the body on which the bushings are mounted. This occurs even when wear cups, which are loosely fitted over the bushings, are used. Various attempts to overcome this have been proposed in prior art devices such as for example, the use of lugs on the bushing which are designed to fit in recessed areas on the housing to prevent rotation of the bushing with respect to the housing. However, such methods increase the difficulty and time required to assemble and disassemble the machine for maintenance. It has also been observed that with the use of lugs in recessed areas it is possible to assemble the devices without having the lug properly positioned in its respective recessed area. Such assembly results in early wear of the bushing and improper operation of the tank-cleaning device. This problem has been overcome by providing bushings 24, 29 and 36 with collars 124, 129 and 136 respectively which are eccentric with respect to the sleeve of the bushing.

Referring to FIG. 4, bushing 29 is coaxially positioned on cylindrical portion 217 of stationary body 11. Point A represents the axis of bushing 29. Collar 129 of bushing 29 is eccentric with respect to the axis of the sleeve of bushing 29. Point B represents the axis of collar 129. A bushing seat defined by the inner surface of depending skirt 122 and bottom edge of adapter 121 is correspondingly eccentric with respect to the axis of the sleeve of bushing 29 and has the axis represented by Point B. In this manner, bushing 29 is restrained from rotation by eccentric collar 129 positioned in the eccentric bushing seat formed in hose adapter 121. In the same manner, bushing 24 is provided with eccentric collar 124 which is received in eccentric bushing seat 125 formed in the upper surface of bevel gear 23. Likewise, both bushings 36 are provided with eccentric collars 136 which are received in bushing seats of corresponding eccentricity formed by cover plate 39 and ring 35. In this manner, wear due to rotation of the second housing 14 and third housing 16 during operation occurs at the outer surfaces of the bushing sleeves and at the inner surfaces of the replaceable wear cups. Improper positioning of the collars in the bushing seats is avoided and assembly of the machine is facilitated.

From the foregoing it is apparent that a new and improved hydraulically operated tank-cleaning apparatus has been provided wherein the gear train is substantially more compact thus allowing for a substantial reduction in the outside diameter of the apparatus of this invention due to reduction in the diameter of the gearbox and cylindrical portion carrying the third rotary housing. Moreover, by the arrangement of spur and pinion gears of the drive train of the apparatus of this invention the reliability and endurance of spur and pinion gears is retained and the problems engendered with prior art devices employing planetary and worm gears is avoided.

From the foregoing description, it is readily apparent how the present invention accomplishes its various objectives. While the invention has been described and illustrated herewith, with reference to certain preferred embodiments thereof, it is to be understood that it may be otherwise embodied within the scope of the appended claims.

I claim:

1. In a tank cleaning apparatus, a source of fluid, a stationary housing having a first interior passageway adapted to be connected to said source of fluid, a second housing rotatably mounted on said stationary housing for rotation about the axis of said stationary housing and having a second interior passageway communicating with said first interior passageway, a third housing rotatably mounted on said second housing for rotation about an axis normal to the axis of said stationary housing having a third interior passageway communicating with said second interior passageway, nozzle means communicating with said third interior passageway carried by said third rotary housing, said nozzle means being offset with respect to the axis of rotation of said third housing, drive means for rotating said third housing as said second housing rotates about said stationary housing, impeller means responsive to the flow of fluid through said first interior passageway, drive means in meshed relationship with said impeller means for rotating said second housing about the axis of said stationary housing, the improvement which comprises a first vertical shaft carrying a plurality of coaxially aligned spur and pinion gear assemblies, said spur and pinion gear assemblies being rotatable with respect to said first shaft and each other spur and pinion gear assembly carried by said shaft, a second vertical rotatable shaft carrying at least one spur and pinion gear assembly, said spur and pinion gear assembly being rotatable with respect to said second shaft and each other spur and pinion gear carried by said second shaft, each of said spur and pinion gear assemblies consisting of a spur gear and a pinion gear coaxially aligned and joined together, said shafts positioned so that said spur and pinion gear assemblies on said first shaft are intermeshed with said spur and pinion gear assembly of said second shaft for rotating said second shaft responsive to the rotation of said impeller means, a ring gear having teeth on its interior circumference being connected to said second housing coaxial of said second housing axis of rotation and a final drive pinion fixed on said housing said second shaft and responsive to the rotation thereof in meshed relationship with said ring gear for driving said ring gear at a substantially slower speed than the rotational speed.

2. The tank-cleaning apparatus of claim 1 wherein said first vertical shaft contains three spur and pinion gear assemblies, each said assembly being rotatable with respect to said first vertical shaft and with respect to each other, said second vertical shaft contains two spur and pinion gear assemblies, each said assembly being rotatable with respect to the other spur and pinion gear assembly and to said shaft, and said second shaft being provided with a final drive pinion gear fixed to said second shaft, each of said shafts positioned with respect to the other so that the spur gear of the lowest spur and pinion assembly of said first vertical shaft is in meshed relationship with a drive pinion of said impeller means and said pinion gears of said assemblies on said first vertical shaft are in meshed relationship with the spur gears of said spur and pinion gear assemblies of said second vertical shaft and the spur gears of said spur and pinion gear assemblies of said second vertical shaft are in meshed relationship with the pinions of said assemblies on said first vertical shaft.

3. The tank-cleaning apparatus of claim 1 wherein said ring gear is provided with at least one outwardly extending lug and said second rotary housing is provided with an inwardly extending stop for contacting said lug during operation whereby rotation of said ring gear is transmitted through said lug and stop to said second rotary housing.

4. The tank-cleaning machine of claim 1 wherein bushing means are coaxially positioned on said cylindrical portion of said stationary housing and cylindrical extension of said second housing for rotation of said second housing on said stationary housing and said third housing on said second housing, said bushing means having collars eccentrically positioned with respect to the axis of said bushing means and received in bushing seats of corresponding eccentricity with respect to said bushing means axis whereby rotation of said bushings is prevented.

5. Tank-cleaning machine of claim 1 wherein said third rotary housing is connected to said drive means by friction clutch means, said friction clutch means responsive to the pressure of fluid flowing through said third rotary housing.

6. Tank-cleaning machine of claim 5 wherein said friction clutch means comprises a resilient clutch ring seated in an annular channel provided in the wall of said third rotary housing adjacent said drive means, said annular channel communicating between said third interior passageway and said drive means whereby fluid pressure acting through said annular channel urges said resilient clutch ring against said drive means and against the sides of said annular channel and said third rotary housing is frictionally engaged with said drive means.

UNETED STATES PATENT OFF ICE CElHIFICATE OF CORRECTION Patent No. 3,637,138 Dated January 25, 1972 Inyentor (s) James H. Rucker I It is certified that error appears in the' 'above-identified patent and that said Letters Patent are hereby "corrected as shown below: l

Column 2, line 65 and 67, reference numeral "l7 should read --2l7--. Column 3, llnes 26, 37 and 40, reference numeral "117", each occurrance, should read -l7--.

Signed and sealed this 5th day of September 12 1/2 Attest:

lflDlfAl'il) 1-'i.i LiTUHER,JR. ROBERT GOTTSGl-iALK Attesting Officer Commissioner of Patents 

1. In a tank cleaning apparatus, a source of fluid, a stationary housing having a first interior passageway adapted to be connected to said source of fluid, a second housing rotatably mounted on said stationary housing for rotation about the axis of said stationary housing and having a second interior passageway communicating with said first interior passageway, a third housing rotatably mounted on said second housing for rotation about an axis normal to the axis of said stationary housing having a third interior passageway communicating with said second interior passageway, nozzle Means communicating with said third interior passageway carried by said third rotary housing, said nozzle means being offset with respect to the axis of rotation of said third housing, drive means for rotating said third housing as said second housing rotates about said stationary housing, impeller means responsive to the flow of fluid through said first interior passageway, drive means in meshed relationship with said impeller means for rotating said second housing about the axis of said stationary housing, the improvement which comprises a first vertical shaft carrying a plurality of coaxially aligned spur and pinion gear assemblies, said spur and pinion gear assemblies being rotatable with respect to said first shaft and each other spur and pinion gear assembly carried by said shaft, a second vertical rotatable shaft carrying at least one spur and pinion gear assembly, said spur and pinion gear assembly being rotatable with respect to said second shaft and each other spur and pinion gear carried by said second shaft, each of said spur and pinion gear assemblies consisting of a spur gear and a pinion gear coaxially aligned and joined together, said shafts positioned so that said spur and pinion gear assemblies on said first shaft are intermeshed with said spur and pinion gear assembly of said second shaft for rotating said second shaft responsive to the rotation of said impeller means, a ring gear having teeth on its interior circumference being connected to said second housing coaxial of said second housing axis of rotation and a final drive pinion fixed on said second shaft and responsive to the rotation thereof in meshed relationship with said ring gear for driving said ring gear at a substantially slower speed than the rotational speed.
 2. The tank-cleaning apparatus of claim 1 wherein said first vertical shaft contains three spur and pinion gear assemblies, each said assembly being rotatable with respect to said first vertical shaft and with respect to each other, said second vertical shaft contains two spur and pinion gear assemblies, each said assembly being rotatable with respect to the other spur and pinion gear assembly and to said shaft, and said second shaft being provided with a final drive pinion gear fixed to said second shaft, each of said shafts positioned with respect to the other so that the spur gear of the lowest spur and pinion assembly of said first vertical shaft is in meshed relationship with a drive pinion of said impeller means and said pinion gears of said assemblies on said first vertical shaft are in meshed relationship with the spur gears of said spur and pinion gear assemblies of said second vertical shaft and the spur gears of said spur and pinion gear assemblies of said second vertical shaft are in meshed relationship with the pinions of said assemblies on said first vertical shaft.
 3. The tank-cleaning apparatus of claim 1 wherein said ring gear is provided with at least one outwardly extending lug and said second rotary housing is provided with an inwardly extending stop for contacting said lug during operation whereby rotation of said ring gear is transmitted through said lug and stop to said second rotary housing.
 4. The tank-cleaning machine of claim 1 wherein bushing means are coaxially positioned on said cylindrical portion of said stationary housing and cylindrical extension of said second housing for rotation of said second housing on said stationary housing and said third housing on said second housing, said bushing means having collars eccentrically positioned with respect to the axis of said bushing means and received in bushing seats of corresponding eccentricity with respect to said bushing means axis whereby rotation of said bushings is prevented.
 5. Tank-cleaning machine of claim 1 wherein said third rotary housing is connected to said drive means by friction clutch means, said friction clutch means responsive to the pressure of fluid flowing through said third rotary housing.
 6. Tank-cleaning machine of claIm 5 wherein said friction clutch means comprises a resilient clutch ring seated in an annular channel provided in the wall of said third rotary housing adjacent said drive means, said annular channel communicating between said third interior passageway and said drive means whereby fluid pressure acting through said annular channel urges said resilient clutch ring against said drive means and against the sides of said annular channel and said third rotary housing is frictionally engaged with said drive means. 